Tube mount support



May 20, 1958 W. '1'. MlLus TUBE MOUNT SUPPORT Filed July 26, 1955 FIG.!

INVENTOR WALTER T. MILLIS,

TUBE MGUNT SUPPORT Walter Townsend Militia, Owensboro, Ky., assignor toGeneral Electric Company, a corporation of New York Application July as,1955, Serial No. 524,563

8 laims. (til. 313-292) My invention relates to electric dischargedevices and pertains more particularly to new and improved means forsupporting an electronic tube mount in a tube envelope.

It is the general practice in supporting the mount structure of anelectronic tube in the envelope of the tube to use devices commonlyknown in the industry as snubbers. Snubbers have been provided tosupport the mount by being fastened to or made a part of the mountstructure and extending outwardly and engaging the inner walls of theenvelope. A common type of snubber currently in use in receiving tubetypes and the like is a bluntpointed projection punched from, orotherwise formed integr lly with, and on the peripheries of mica disksor electrode spacers, which comprise parts of the tube mount. This typeof snubber, from the standpoint of cost, is decidedly advantageous overother types that are formed separately and have to be subsequentlyattached to the tube mount. The integrally formed projections heretoforeprovided have, however, the disadvantages of being inflexible and ofhaving a tendency to be crushed when inserted into a tube envelope. Suchcrushing results in a substantial reduction in the dimensions of theprojection and thus a loose fit or poor mount rigidity follows, causingundesired microphonics and rattling of parts when the tube is tapped orotherwise vibrated. The tendency toward crushing of the snubber isincreased when the envelope is out of round or when the eifectivediameter of the open end of the tube bulb, through which the spacermustpass on assembly, is for any reason smaller than that of the normalstraight wall portion of the bulb. Further, forces tending to crush thetips of the snubbers occur during shipping and handling of the completedtubes.

Still further, when the spacers are formed of mica or the like, thecrushing or breaking of the snubbers results in the undesirable presencein the tube of flakes or particles of the spacer material which tendadversely to affect tube operation.

Accordingly, the primary object of my invention is to provide a new andimproved tube mount support means.

Another object of my invention is to provide a new and improved snubberstructure adapted for insuring a satisfactory fit thereof in an envelopeand thereby avoid mount rattle and tube noise.

Another object of my invention is to provide a new and improved snubberstructure adapted for avoiding crushing of any portions thereof therebyto insure a satisfactory fit in an envelope and to avoid the presence inthe envelope of undesired loose particles of matter which would tendadversely to affect the operation of the tube.

Another object of my invention is to provide a new and improved snubberstructure which, in addition to insuring satisfactory transverse fit ina tube envelope, is adapted to assist in minimizing longitudinalmovement of the tube mount and thereby increase rigidity of the mount inthe tube envelope.

Still another object of my invention is to provide new fitates Patentdie;

and improved integrally formed snubbers and iusulative mount supportthereby to take advantage of the cost reductions available through thispractice.

Purher objects and advantages of my invention will become apparent asthe following description proceeds and the features of novelty whichcharacterize my *2 w"l be pointed out with particularity in the iexed toand forming part of this specification.

in carrying out the objects of my invention, l have provided aninsulative member including a plurality of outwardly extending fingersof sufiicient length to insure bending thereof rather than breakage uponinsertion into a tube envelope. The fingers may be of different lengthsto compensate for variations in bulb sizes and configurations and toadapt the supports for use in a wide range of bulb sizes. The fingersmay extend at oblique angles thereby to provide for maximum fingerlength with minimum consumption of the body portion of the member.

For a better un-Cerstanding of my invention, reference may be had to thedrawing in which:

Fig. 1 is a partially sectionalized view illustrating a step in theassembly of device in which my invention may be incorporated;

Fig. 2 is a partially broken away view of a tube incorporating myinvention;

Fig. 3 is a sectional view taken along the line of Fig. 2 showing aninsulative support formed in accordance with one embodiment of myinvention;

Fig. 4 is a sectional view taken along the line i---t in Pig. 3 andlooking in the direction of the arrows;

Fig. 5 is a plan view of a modified form of my invention;

Pig. 6 is a fragmentary sectional view taken along the line 66 in Fig. 5and looking in the direction of the arrows;

Fig. 7 is a plan view of a further modified form of my invention;

Fig. 8 is an enlarged fragmentary plan view of an insulative supportconstructed in accordance with a still further embodiment of myinvention; and

Fig. 9 is an enlarged fragmentary plan view of an insulative supportconstructed in accordance with still another embodiment of my invention.

Referring to Fig. l, l have illustrated the manner in which, during theusual assembly of an electronic tube, a tube mount l is positioned forinsertion into a sub stantially cylindrical bottle or bulb L The mount 1comprises a plurality of electrodes generally designated 3 and mountedbetween a spaced pair of insulative supports or spacers 4 as by havingend portions extend through suitabie apertures in the supports. Themount is supported atop an insulative stem E by having portions of theelectrodes suitably connected to portions of leads 6 which extend in asealed manner through the stem 5.

Heretofore, it has been the practice to construct or form the insulativespacers d of mica and to include small integral pointed tips or snubberswhich engaged the inner wall of the envelope 2 when the mount wasinserted into the bulb. These tips were intended to insure a tight fitof the supports in the bulb thereby to provide for rigidity of the mountand to reduce tube noise. However, it was found that often the walls ofthe bulb were not straight as intended with the result that the lower oropen end of the bulb was sometimes out of round or smaller in diameterthan the major portion, in the manner indicated by the dot and dashlines designated 2 in Fig. 1. As a result when the mount was inserted orpassed into the bulb the small pointed snubbers had a tendency readilyto crush and break off, causing a loose fit of the supports in the bulband the presence of undesirable loose particles in the envelope. Alsowhere the pointed snubbers did not entirely break off, a marked tendencywas observed for one or more of the laminations of which the pointedsnubbers were constituted to break off, thereby introducing bits ofsupport material into the bulb and rendering the remaining portion ofthe pointed snubbers more likely to break oil. in response to continuedvibration of the tube. Furthermore, such pointed snubbers, weakened bythe fracture of one or more laminaticns failed eificiently to performthe function of rigidly supporting the mount.

As seen in Figs. 2 and 3, my invention contemplates the provision ofinsulative supports or disks 4 which are formed to include a pluralityof elongated radially extending circumferentially spaced fingers 1dwhich are of sufficient radial length to insure flexibility or bendingthereof without breakage or crushing of individual fingers or ofindividual lamina of which the fingers are constituted during insertionof the mount into the bulb 2. This desired flexibility can be obtainedby forming the supports 4 of mica or similar insulative material havinga thickness in the range of .005 to .020 of an inch and by dimensioningthe fingers 16 so that the radial lengths thereof are greater than thewidth at the root or innermost portion of the fingers.

I have found that when so proportioned the bending moment, to which suchfingers are exposed during the insertion of the mount in anon-concentric bulb, is insufficient to cause fracture either of thefingers as a whole or of individual laminations of which the fingers areconstituted. Accordingly, the undesired features of the prior artconstructions residing in the looseness of fit, the introduction ofloose elements in the bulb, and the production of weakened snubbers arelargely obviated.

Additionally, the fingers 10 are of such length that the outermost endsor tips thereof define a circle or area just slightly greater than thenormal internal diameter or cross-sectional area, respectively, of thebulb 2. As a result, resilient bent engagement of the fingers with thewalls of the bulb, in the manner shown in Figs. 2, 3 and 4, is insured.

According to a modification of my invention and as shown in Fig. 5, thesupports 4 may be formed to include a plurality of radially extendingcircumferentially spaced secondary fingers 11 in addition to the fingers1d of the above-described embodiment. These fingers may also be formedso as to be greater in radial length than in width at the roots thereof;and thus, like the fingers 10 are rendered more flexible, and thusminimize the tendency to fracture. The fingers 11 which, as shown are ofrelatively shorter radial dimension than fingers 10, are preferably eachinterposed between a pair of the fingers It? in the manner illustrated,and the outermost portions or tips thereof may define a circle or areasubstantially the same as the normal inner diameter or cross-sectionalinternal area, respectively, or the bulb 2.

As seen in Figs. 5 and 6 the longer fingers 1t bend or flex in themanner illustrated but do not crush or break nor do any of theindividual lamina flake off. The degree of bending of each of thefingers 14B depends on the trueness of the engaged portions of the bulbwalls to the desired cross sectional shape of the bulb 2. Additionally,the shorter fingers 11 tend to engage the inner wall of the bulb orenvelope without bending in the manner shown in Fig. 6. However, in theevent that the bulb is out of round some of the fingers 11 may also bendin a manner similar to the fingers 10.

As also seen in Fig. 6 and as a result of the difference in lengths, thefingers li and 11 tend to engage the inner wall of the bulb 2 atdifferent levels. This results in improved resistance to longitudinalmovement of the mica support in the envelope, which in turn provides forincreased rigidity of the mount 1.

It will be understood that my invention is equally applicable tocomposite insulative supports. For example, and

as shown in Fig. 7, my invention may comprise an annular member 12, or amember of any other configuration which provides a central opening, andan insulative strip 13 secured across the opening and adapted forreceiving and supporting electrode elements. The composite electrodemount structure including the annular member 12 and strip 13 is not myinvention but is disclosed and claimed in co-pending U. S. applicationSerial No. 504,957, I. F. Stephens, filed April 29, 1955, and assignedto the same assignee as the present invention. The mem- 12 may be formedof the same material and to the same thickness as the above-describedsupport 4. Additionally, the member 12 may be formed to include fingersidentical to the fingers 19 and 77 and, accrdingly, having the samenumerical designation.

In Fig. 8 is illustrated another embodiment of my sup port generallydesignated 15. In this embodiment also the support may be formed of micain the range of thicknesses from .005 to .020 of an inch. Additionally,the support 15 is formed to include a plurality of elongated radiallyextending flexible fingers 16 of substantially parallel sides and whichare spaced circumferentially about the support at somewhat less spacingbetween adjacent fingers than the elongated fingers of theabovedescribed embodiments. However, like the fingers of the describedembodiments, the fingers 16, in order to provide the desired flexibilityand resistance to fracture, are greater in length than in width at theroot thereof or where the fingers are attached to the 'body portion ofthe support. Additionally, the outermost portions or ends of the fingers16 define an area slightly greater than the normal insidecross-sectional area of the bulb 2. If the bulb is cylindrical the endsof the fingers 16 will define a circle slightly greater in diameter thanthe normal inside diameter of the bulb.

Formed between the elongated fingers 16 are shorter parallel sidefingers 17 which are also greater in length than in Width and whichdefine an area or a circle substantially the same as that defined by thenormal inner wall of the bulb 2. The support 15 is adapted for fittingin the bulb 2 in substantially the same manner as the support 4described above; however, the increased number of fingers are adaptedfor insuring a tighter fit in the bulb and increasing the rigidity ofthe mount 1.

In Fig. 9 is illustrated a third embodiment of my invention generallydesignated Ztl. The support 20 may be formed of the same material andthickness as the abovedescribed embodiments and includes a plurality ofelongated flexible fingers 21 corresponding generally to the fingers 16and a plurality of alternately disposed shorter fingers 22 correspondinggenerally to the fingers 17 in Fig. 8. Like the fingers of the first andsecond embodiments, the fingers 21 and 22 each are longer or greater inlength than in width at the roots or portions at which they attach tothe body of the support Zfi. Additionally, fingers 21 and 22 all extendobliquely or at acute angles to the radii of the support 20. Thispermits the fingers to be formed of greater length, and consequentlyprovide greater flexibility and resistance to fracture, while consuminga minimum amount of the body portion of the support 2t Additionally, theoutermost'points or portions of the fingers 21 define a circle slightlygreater in diameter than the normal inner diameter of the bulb 2 and theoutermost tips or portions of the fingers 2.2. define a circlesubstantially equal in diameter to the normal inner diameter of the bulb2. If the bulb is other than cylindrical the support 2i can be formed sothat the tips of the fingers 21 and 22 will define areas slightlygreater and the same as, respectively, the inner cross-sectional area ofthe bulb. The support 29 is adapted for being used in substantially thesame manner as described above with regard to the first embodiment.

Thus, it will be seen that I have provided a new and .improvedinsulative support which is adapted for insuring a tight fit of a tubemount in an envelope regardless of substantial variations orirregularities in the envelope configuration thereby to insure lateralrigidity of the mount and to minimize noise during tube operation.Additionally, my structure insures against breakage of any portions ofthe support during assembly, shipping and use and thereby prevents thepresence of undesirable loose pan ticles of the support material in thetube. Still further, my support is adapted to provide increasedlongitudinal rigidity of the mount in the tube.

While I have shown and described specific embodiments of my invention, 1do not desire my invention be limited to the particular forms shown anddescribed and I intend by the appended claims to cover all modificationswithin the spirit and scope of my invention.

What I claim as new and desire to secure by Letters Fatent of the UnitedStates is:

1. l/ieans for supporting a structure in an envelope having an axis,comprising an insulative planar disk-like mem er adapted for beingpositioned transversely in said envelope, said member including aplurality of projections integral with and extending from the outer edgethereof, said projections being greater in length than in width at thebases thereof and thereby adapted for bending engagement with saidenvelope without fracture of said projections when said member ispositioned in said envelope.

2. Means for supporting a structure in an envelope comprising aniusulative member adapted for being positioned transversely in saidenvelope, said member including a plurality of outwardly extendingcircumferentially spaced fingers formed off the periphery thereof, saidfingers defining an area slightly greater than the cross-sectionalinternal area of said envelope, said fingers being greater in lengththan in Width at the innermost portions thereof and thereby adapted forbending and avoiding breakage thereof when said member is positioned insaid envelope.

3. Means for supporting electrode elements in insulated spaced relationin an envelope comprising a mica member adapted for being positionedtransversely in said envelope and having a thickness in the range offrom .005 to .020 of an inch, said member including a plurality ofoutwardly extending circumferentially spaced fingers formed oil? theperipheral edge of said member defining an area slightly greater thanthe cross-sectional internal area of said envelope, said fingers beinggreater in length. than in width at the root portions thereof andthereby adapted for bending and avoiding breakage of said fingers orindividual lamina constituting said fingers when said member ispositioned in said envelope.

4. Means for supporting a structure in an envelope comprising an insulave member adapted for being posi tioned transversely in said envelope,said member including a first plurality of outwardly extendingcircumferentially spaced fingers defining an area slightly greater thanthe cross-sectional internal area of said envelope, and a secondplurality of circurnierentially spaced fingers interposed between thefingers comprising said first plurality and defining an areasubstantially the same as the cross-sectional internal area of saidenvelope, said fingers being greater in length than in width at the rootportions thereof and thereby adapted for bending and avoiding breakagewhen said member is positioned in said euvelope.

5. Means for supporting electrode elements in insulated spaced relationin an envelope comprising a mica member adapted for being positionedtransversely in. said envelope and having a thickness in the range offrom .005 to .020 of an inch, said member including a first plurality ofoutwardly extending circumferentially spaced fingers formed off saidmember and defining an area slightly greater than the cross-sectionalinternal area of said envelope, and a second plurality of outwardlyextending circumferentially spaced fingers interposed between thefingers comprising :1 first morality and defining an area substantiallythe same as the cross-sectional internal area of said envelope, saidfingers being greater in length than in width at the innermost portionsthereof and thereby adapted for bendi g and avoiding breakage of saidfingers or individual u'na constituting said fingers when said member isposi tioned in said envelope.

6. Means for supporting a structure in an envelope comprising a memberadapted for being positioned transversely in said envelope, said memberincluding a plurality of outwardly and obliquely extendingcircumferentially spaced fingers, the outermost portions of said fingersdefining an area slightly greater than the cross-sec tional area of saidenvelope, said fingers being greater in length than in width and therebyadapted for bending and avoiding breakage when said member is positionedin said envelope.

7. Means for supporting electrode elements in insulated spaced relationin an envelope comprising a mica member adapted for being positionedtransversely in said envelope and having a thickness in the range offrom .005

to .020 of an inch, said member including a plurality of outwardlyobliquely extending circumferentially spaced fingers, the outermostportions of said fingers defining an area slightly greater than thecross-sectional internal area of said envelope, said fingers beinggreater in length than in width at the base thereof and thereby adaptedfor bending and avoiding breakage of said fingers or individual laminaconstituting said fingers when said member is positioned in saidenvelope.

8. Means for supporting a structure in an envelope comprising a memberadapted for being positioned transversely in said envelope, said memberincluding a first plurality of outwardly and obliquely extendingcircumferentially spaced fingers, the outermost portions of said fingersdefining an area slightly greater than the cross-sectional internal areaof said envelope, and a second plurality of outwardly and obliquelyextending circumferentially spaced fingers, the outermost edges of saidlast-mentioned fingers defining an area substantially the same as thecross-sectional internal area of said envelope, said fingers beinggreater in length than in width at the innermost portions thereof andthereby adapted for bending and avoiding breakage when said member ispositioned in said envelope.

References Cited in the file of this patent UNITED STATES PATENTS1,974,086 Smith Sept. 18, 1934 1,982,069 Reed Nov. 27, 1934 2,078,371Daene Apr. 27, 1937 2,527,166 Walsh Oct. 24, 1950

